Submerged arc welding system with pressurized flux delivery and welding torch

ABSTRACT

A submerged arc welding system includes a robot having a first arm connected to a second arm, and at least one wire supply. A welding torch is connected to a first end of the second arm of the robot. A wire motor is mounted to a second end of the second arm of the robot. The wire motor moves wire from the wire supply along a wire path to the welding torch. The system further includes a flux supply and a flux delivery system configured to move flux from the flux supply along a flux path to the welding torch.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.12/504,411 filed in the United States Patent and Trademark Office onJul. 16, 2009, which is currently pending. The entirety of thisApplication is incorporated herein by reference.

FIELD OF INVENTION

The present application relates to a submerged arc welding system. Moreparticularly, the present application relates to an automatic submergedarc welding system with a pressurized flux delivery system.

BACKGROUND

Submerged arc welding is a type of welding where the arc is completelysubmerged in a covering of granular fusible flux. The flux protects themolten weld puddle from atmospheric contamination. Submerged arc weldingsystems, like other types of welding systems, may include a weldingpower supply, a wire feed control and drive assembly and a weldingtorch. In addition, submerged arc welding systems also include a fluxsystem. The flux system holds and delivers the flux to the weld jointduring welding.

SUMMARY

A submerged arc welding system includes a robot having a first armconnected to a second arm, and at least one wire supply. A welding torchis connected to a first end of the second arm of the robot. A wire motoris mounted to a second end of the second arm of the robot. The wiremotor moves wire from the wire supply along a wire path to the weldingtorch. The system further includes a flux supply and a flux deliverysystem configured to move flux from the flux supply along a flux path tothe welding torch.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings, structures are illustrated that, togetherwith the detailed description provided below, describe exemplaryembodiments of the claimed invention.

In the drawings and description that follows, like elements areidentified with the same reference numerals. The drawings are not toscale and the proportion of certain elements may be exaggerated for thepurpose of illustration.

FIG. 1 is a perspective view of one embodiment of a submerged arcwelding system attached to a robot;

FIG. 2 is a side view of one embodiment of a welding torch of thesubmerged arc welding system shown in FIG. 1;

FIG. 3 is a partial cross-section of one embodiment of a vent chamber ofa flux muffler for a welding torch of the submerged arc welding system;

FIG. 4 is a partial cross-section of one embodiment of a valve for awelding torch of the submerged arc welding system;

FIG. 5 is a side view of an alternative embodiment of a welding torch ofthe submerged arc welding system;

FIG. 6 is a partial cross-section of an alternative embodiment of a ventchamber of a flux muffler for a welding torch of the submerged arcwelding system; and

FIG. 7 is a partial cross-section of another alternative embodiment of avent chamber of a flux muffler for a welding torch of the submerged arcwelding system.

DETAILED DESCRIPTION

FIG. 1 is a perspective view of a submerged arc welding system 100 usedwith a robot R. In the illustrated embodiment, the robot R has a base B,a first arm A1, and a second arm A2. The first arm A1 is rotatablyconnected to the base B and is configured to rotate about a first axisX1 and a second axis X2. The second arm A2 is rotatably connected to thefirst arm A1 and is configured to rotate about a third axis X3 and afourth axis X4. In the illustrated embodiment, the robot R furtherincludes a torch mounting bracket M, connected to the second arm A2,that articulates about a fifth axis X5 and sixth axis X6. In one knownembodiment, the robot R is the ARC MATE 120iBe manufactured by FANUCROBOTICS. However, it should be understood that the illustrated robot Ris merely exemplary, and that the submerged arc welding system 100 maybe employed with any robot or robotic arm.

In the illustrated embodiment, the submerged arc welding system 100includes a welding torch 105 comprising a power block 110, a weldingtorch cable 115, and a nozzle 120. The welding torch cable 115 mayinclude an optional liner. In an alternative embodiment (not shown), thewelding torch includes a power block, a torch power connection, and awire conduit and welding cables configured to handle required amperageconnected to the power block. In one known embodiment, the welding torch105 weighs less than 20 kilograms. The welding torch 105 is connected tothe second arm A2 of the robot R by the torch mounting bracket M. In analternative embodiment, the welding torch 105 is directly connected tothe second arm A2.

A wire supply 125 supplies welding wire 130 to a wire motor 135, whichfeeds the welding wire 130 through the welding torch cable 115 of thewelding torch 105 and subsequently through the nozzle 120. In otherwords, the wire motor 135 moves the welding wire 130 from the wiresupply 125 along a wire path though the nozzle 120 of the welding torch105, wherein the wire path includes the wire motor 135 and the weldingtorch cable 115. The wire supply 125 is shown as a single spool ofwelding wire, but it should be understood that the wire supply 125 mayinclude two or more wire supplies, such as a first spool of welding wireand a second spool of welding wire. Where two or more wire supplies areemployed, a corresponding number of wire motors and welding torch cablesare employed. In other alternative embodiments (not shown), the wiresupply 125 may take the form of a reel, spool, drum, or box container.

In the illustrated embodiment, the wire supply 125 is not directlymounted to the robot R. Instead, the wire supply 125 is located distalfrom the robot R. The wire supply 125 may be located any distance fromthe robot R, such that it may be placed in a position suitable for aparticular environment. In most known welding environments, the wiresupply 125 will be located between about 1 meter to about 50 meters fromthe robot R.

The wire motor 135 is shown mounted to the first arm A1 of the robot R,behind the third and fourth axes. In alternative embodiments (notshown), the wire motor 135 may be mounted to the second arm A2 of therobot R, or placed in a location not connected to the robot R.

Additionally, the submerged arc welding system 100 includes a fluxsupply 140 that supplies flux through a flux line 145 to the weldingtorch 105. The flux includes granular fusible flux particles. The fluxparticles may include lime, silica, manganese oxide, calcium fluoride,or a combination thereof. The flux may also include flux fines (i.e.,small particles) and dust of the same or similar composition as the fluxparticles.

In one embodiment, the flux supply 140 includes a vacuum unit (notshown) having a hose extending adjacent the nozzle 120. The hose andvacuum unit are configured to use suction to collect flux particles thatpass through the nozzle 120 and remain on a surface.

In one embodiment, the flux supply 140 includes a pressurized fluxdelivery system that employs pressurized air to push or otherwise moveflux through the flux line 145, wherein the flux line 145 is directlyconnected to the welding torch 105. The flux supply 140 is shown as afeed tank, such as a pressurized feed tank. There is no interveninggravity hopper disposed between the flux supply 140 and the weldingtorch 105. In other words, the pressurized flux delivery system movesthe flux along a flux path from the flux supply 140 to the nozzle 120 ofthe welding torch 105, wherein the flux path does not include a gravityhopper.

The flux supply 140 is not directly mounted to the robot R. Instead, theflux supply 140 is located distal from the robot R. The flux supply 140may be located any distance from the robot R, such that it may be placedin a position suitable for a particular environment. In most knownwelding environments, the flux supply 140 will be located between about1 meter to about 20 meters from the robot R.

The submerged arc welding system 100 may also include a flux recyclingsystem (not shown) for recycling flux that is discharged through thenozzle 120. The flux recycling system may include one or more vacuumtubes that lead back to the flux supply 140 or to the flux line 145,thereby allowing discharged flux to be reused.

Additional details of the welding torch 105 and other components of thesubmerged arc welding system 100 can be seen in FIGS. 2-4. FIG. 2illustrates a side view of one embodiment of the welding torch 105. Thewelding torch 105 includes a flux muffler 150 disposed along the fluxpath and connected to the flux line 145. In the illustrated embodiment,the flux muffler 150 is adjacent to and connected with the welding torch105. In an alternative embodiment, the flux muffler 150 is integral withthe welding torch 105. In another alternative embodiment, the fluxmuffler 150 is spaced from the welding torch.

FIG. 3 illustrates a partial cross-section of the flux muffler 150. Theflux muffler 150 includes a vent chamber 155 inside a casing 160. Thevent chamber 155 has at least one vent 165 configured to removepressurized air from the flux path. In the illustrated embodiment, thevent chamber 155 is a tubular conduit having an input 170, an output175, and a plurality of elongated vents 165. In an alternativeembodiment, the vent chamber may have a square, rectangular, or othergeometric cross-section.

In the illustrated embodiment, the input 170 of the vent chamber 155 issmooth and has an outer diameter smaller than the inner diameter of theflux line 145, such that the input 170 may be inserted into the fluxline 145. The flux line 145 may have elastic properties to maintain aconnection with the vent chamber 155. In an alternative embodiment (notshown), the flux line 145 may be clamped onto the input 170 of the ventchamber 155. In other alternative embodiments, the input 170 of the ventchamber 155 may be threaded, or may have a snap-fit or otherconfiguration to be connected to the flux line 145.

In the illustrated embodiment, the output 175 of the vent chamber 155 isa threaded end, configured to be connected to a lower portion of theflux line 145. In alternative embodiments (not shown), the output 175 ofthe vent chamber 155 may be a smooth end, a snap-fit connector, or otherknown connector.

The vents 165 of the vent chamber 155 may be dimensioned to allow air topass through without allowing flux particles to pass through. In theillustrated embodiment, the casing 160 surrounds the vent chamber 155and is configured to capture any flux fines, dust, or other fluxparticles that pass through the vents 165 of the vent chamber 155. Thecasing 160 is open at the top to allow air to escape to the environmentand includes a filter F to capture flux fines and dust, preventing themfrom passing through the open top. Exemplary filters include steel wool,or other fibrous materials that will allow air movement but restrictsthe flux fines. In the illustrated embodiment, the filter F is onlylocated in an upper portion of the casing 160. In an alternativeembodiment (not shown), the filter F extends to the bottom of the casing160. In another alternative embodiment (not shown), the casing 160 doesnot include a filter. In yet another alternative embodiment (not shown),the casing 160 is closed at the top.

As shown in both FIGS. 2 and 3, the casing 160 is connected to asecondary flux line 180 that forms a path for the escaped flux fines,dust, and other flux particles. This path may be referred to as a fluxfines path, a flux return path, or a flux recycling path.

In the illustrated embodiment, the secondary flux line 180 isreconnected to the flux line 145 below the flux muffler 150 and abovethe nozzle 120. In this manner, the escaped flux fines, dust, and otherflux particles are recycled and rejoin the other flux particles. Thisprocess may be referred to as recycling, even though it occurs beforethe flux passes through the nozzle 120. The flux line 145 is connectedto the nozzle 120 such that the flux and the recycled flux fines, dust,and other flux particles travel through the flux line 145 and passthrough the nozzle 120. In one embodiment (not shown), the nozzle alsoincludes vent to evacuate remaining air to the environment.

With continued reference to FIG. 2, a flux valve 185 is located alongthe flux line 145, and is configured to control the release of flux fromthe flux path to the nozzle 120 of the welding torch 105. In theillustrated embodiment, the flux valve 185 is directly below the fluxmuffler 150 and spaced from the nozzle 120 of the welding torch 105. Inan alternative embodiment, the flux valve may be adjacent the nozzle 120of the welding torch 105.

In one known embodiment, the flux valve 185 is a SPARTAN SCIENTIFICSERIES APV-23 valve. In alternative embodiments, the flux valve 185 is apinch, gate, or a butterfly style valves. In one embodiment, the fluxvalve 185 is normally biased in a closed position to prevent flux fromaccidentally being discharged through the nozzle 120.

FIG. 4 illustrates a partial cross-section of the flux valve 185. Theflux valve 185 is substantially cylindrical and includes a piston 190configured to extend into and seal a tube 195. The piston 190 is furtherconfigured to be retracted from the tube 195, thereby creating anopening along flux to pass through. The flux valve 185 may include aspring extended pneumatic operator to control extension or retraction ofthe piston 190.

FIG. 5 illustrates a side view of an alternative embodiment of a weldingtorch 200 that is substantially the same as the welding torch 105 exceptfor the differences described herein. The alternative welding torch 200includes an alternative flux muffler 205.

A partial cross-section of the alternative flux muffler 205 isillustrated in FIG. 6. The flux muffler 205 is substantially the same asthe flux muffler 150, except for the differences described herein. Thealternative flux muffler 205 includes a vent chamber 210 in a casing215. However, the casing 215 is not connected to secondary flux lineleading towards the nozzle of the welding torch. Instead, the casing 215is connected to a vacuum tube 220 that leads away from the nozzle andforms a path for the escaped flux fines, dust, and other flux particles.

In one embodiment, the vacuum tube 220 is connected to the flux supply.In an alternative embodiment, the vacuum tube 220 is connected to theflux line. In both embodiments, escaped flux fines, dust, and other fluxparticles are reused. This process may be described as recycling, eventhough it occurs before the escaped flux fines, dust, and other fluxparticles are discharged through the nozzle.

In the illustrated embodiment, the casing 215 is open at the top andincludes an internal filter F to capture flux fines and dust, preventingthem from passing through the vents. Exemplary filters include steelwool, or other fibrous materials that will allow air movement butrestricts the flux fines. In the illustrated embodiment, the filter F isonly located in an upper portion of the casing 215. In an alternativeembodiment (not shown), the filter F extends to the bottom of the casing215. In another alternative embodiment (not shown), the casing 215 doesnot include a filter. In yet another alternative embodiment (not shown),the casing 215 is closed at the top.

FIG. 7 illustrates another alternative embodiment of a flux muffler 300.In this embodiment, the flux muffler 300 is substantially the same asthe flux muffler 150 and the alternative flux muffler 205, except theflux muffler 300 includes a casing 305 having a plurality of vents 310.The flux muffler 300 does not include a secondary flux line or a vacuumtube. Instead pressurized air is simply evacuated through the vents tothe environment.

In the illustrated embodiment, a vent chamber 315 inside the casing alsohas a plurality of vents (not shown). In one embodiment, the fluxmuffler 300 further includes an internal filter disposed between thevent chamber 315 and the casing 305 to capture flux fines and dust,preventing them from passing into the environment. Exemplary filtersinclude steel wool, or other fibrous materials that will allow airmovement but restricts the flux fines.

To the extent that the term “includes” or “including” is used in thespecification or the claims, it is intended to be inclusive in a mannersimilar to the term “comprising” as that term is interpreted whenemployed as a transitional word in a claim. Furthermore, to the extentthat the term “or” is employed (e.g., A or B) it is intended to mean “Aor B or both.” When the applicants intend to indicate “only A or B butnot both” then the term “only A or B but not both” will be employed.Thus, use of the term “or” herein is the inclusive, and not theexclusive use. See, Bryan A. Garner, A Dictionary of Modern Legal Usage624 (2d. Ed. 1995). Also, to the extent that the terms “in” or “into”are used in the specification or the claims, it is intended toadditionally mean “on” or “onto.” Furthermore, to the extent the term“connect” is used in the specification or claims, it is intended to meannot only “directly connected to,” but also “indirectly connected to”such as connected through another component or components.

While the present application has been illustrated by the description ofembodiments thereof, and while the embodiments have been described inconsiderable detail, it is not the intention of the applicants torestrict or in any way limit the scope of the appended claims to suchdetail. Additional advantages and modifications will readily appear tothose skilled in the art. Therefore, the application, in its broaderaspects, is not limited to the specific details, the representativeapparatus and method, and illustrative examples shown and described.Accordingly, departures may be made from such details without departingfrom the spirit or scope of the applicant's general inventive concept.

What is claimed is:
 1. A submerged arc welding system for use with arobot having a base, a first arm rotatably connected to the base, and asecond arm rotatably connected to the first arm, the submerged arcwelding system comprising: a welding torch having a nozzle, the weldingtorch being connected to the end of the second arm of the robot; a wiresupply; a wire path connecting the wire supply to the welding torch; awire motor configured to move wire from the wire supply along the wirepath to the welding torch, the wire motor being mounted to the robot ata location other than the second arm; a flux supply; a flux pathconnecting the flux supply to the welding torch; and a flux mufflerdisposed along the flux path, the flux muffler comprising a casing, anda conduit within the casing forming a vent chamber that is interior ofthe casing, the vent chamber having a vent for evacuating air from theflux path, the flux muffler further comprising a filter within thecasing and exterior of the vent chamber and configured to capture fluxfines.
 2. The submerged arc welding system of claim 1, wherein the wiremotor is mounted to the first arm of the robot.
 3. The submerged arcwelding system of claim 1, wherein the wire motor is mounted to a baseof the robot.
 4. The submerged arc welding system of claim 1, whereinthe wire path converges with the flux path at the nozzle of the weldingtorch.
 5. The submerged arc welding system of claim 1, wherein the fluxpath does not include a gravity hopper.
 6. A submerged arc weldingsystem comprising: a robot including a first arm connected to a secondarm; at least one wire supply; a welding torch connected to a first endof the second arm of the robot; a wire motor mounted to a second end ofthe second arm of the robot, the wire motor moving wire from the wiresupply along a wire path to the welding torch; a flux supply; a fluxdelivery system configured to move flux from the flux supply along aflux path to the welding torch; and a flux muffler disposed along theflux path, the flux muffler comprising a casing, and a conduit withinthe casing forming a vent chamber that is interior of the casing, thevent chamber having a vent for evacuating air from the flux path, theflux muffler further comprising a filter within the casing and exteriorof the vent chamber and configured to capture flux fines.
 7. Thesubmerged arc welding system of claim 6, wherein the welding torchincludes a nozzle, and the wire path and the flux path converge at thenozzle.
 8. The submerged arc welding system of claim 7, furthercomprising a flux valve disposed along the flux path, adjacent to thenozzle.
 9. The submerged arc welding system of claim 6, wherein the fluxsupply is distal from the robot.
 10. The submerged arc welding system ofclaim 6, wherein the wire supply is distal from the robot.
 11. Thesubmerged arc welding system of claim 6, further comprising a fluxreturn path connecting the vent to the flux path.
 12. An automaticsubmerged arc welding system comprising: a welding torch having anozzle; a flux supply; means for transporting flux from the flux supplyalong a flux path to the nozzle of the welding torch; a wire supply;means for transporting wire from the wire supply along a wire path tothe nozzle of the welding torch, such that the flux path converges withthe wire path at the nozzle; and a flux muffler disposed along the fluxpath, the flux muffler comprising a casing, and a conduit within thecasing forming a vent chamber interior of the casing, the vent chamberhaving a vent for evacuating air from the flux path, the flux mufflerfurther comprising a filter within the casing and exterior of the ventchamber and configured to capture flux fines.
 13. The automaticsubmerged arc welding system of claim 12, further comprising a roboticarm.
 14. The automatic submerged arc welding system of claim 13, whereinwelding torch is connected to a first end of the robotic arm.
 15. Theautomatic submerged arc welding system of claim 14, wherein the meansfor transporting wire is mounted to a second end of the robotic arm. 16.The automatic submerged arc welding system of claim 13, wherein therobotic arm includes a first arm connected to the second arm.
 17. Theautomatic submerged arc welding system of claim 16, wherein the meansfor transporting wire is mounted to the first arm, and the welding torchis connected to the second arm.
 18. The submerged arc welding system ofclaim 1, further comprising: a recycle line connected to the casing ofthe flux muffler to transport from the flux muffler further flux finesthat pass through the vent; and a flux valve disposed along the fluxpath between the flux muffler and the nozzle of the welding torch. 19.The submerged arc welding system of claim 6, further comprising: arecycle line connected to the casing of the flux muffler to transportfrom the flux muffler further flux fines that pass through the vent; anda flux valve disposed along the flux path between the flux muffler and anozzle of the welding torch.
 20. The automatic submerged arc weldingsystem of claim 12, further comprising: a recycle line connected to thecasing of the flux muffler to transport from the flux muffler furtherflux fines that pass through the vent; and a flux valve disposed alongthe flux path between the flux muffler and the nozzle of the weldingtorch.